RESUMO A compactação do solo e a degradação das pastagens muitas vezes são provenientes da pressão exercida pelo casco dos animais. Nesse sentido, objetivou-se verificar possíveis modificações no solo e mudanças na cobertura vegetal da pastagem devido ao pisoteio animal. Assim, um estudo foi realizado em uma fazenda na região do Agreste de Pernambuco, Brasil. Em uma área de 40 × 40 m manejada sob pastejo contínuo, com uma taxa de lotação de 12 UA ha-1; as amostras de solo foram coletadas antes e após o período de pastejo, com 36 pontos distribuídos regularmente. Em cada ponto, determinou-se a densidade, porosidade total, umidade e resistência à penetração do solo na profundidade de 0-0,10 m, bem como a condutividade hidráulica e a matéria orgânica na superfície do solo. Antes e após o pastejo, imagens do satélite Sentinel-2A também foram obtidas para observar o padrão de resposta da vegetação da pastagem ao longo do tempo por meio do Índice de Vegetação por Diferença Normalizada (NDVI) e Cobertura Vegetal de Pastagem (CVP). Os atributos físico-hídricos do solo foram submetidos a análise fatorial. Os mapas de NDVI e CVP foram avaliados quanto à variabilidade espacial. Após o período de pastejo, houve alteração nos atributos do solo em estudo devido ao pisoteio dos animais. O sensoriamento remoto (NDVI e CVP) destacou padrões de variação, como a redução da pastagem e possíveis áreas de preferencias dos animais.

ABSTRACT Soil compaction and pasture degradation are often due to the pressure exerted by the animals’ hooves. In this sense, this study aimed to verify possible changes in the soil and changes in the pasture vegetation coverage due to animal trampling. Thus, a study was carried out on a farm in the ‘Agreste’ region of Pernambuco, Brazil. Soil samples were collected before and after the grazing period, with 36 points regularly distributed in an area of 40 × 40 m managed under continuous grazing, with a stocking rate of 12 AU ha-1. At each point, density, total porosity, humidity, and penetration resistance of the soil at a depth of 0-0.10 m, as well as hydraulic conductivity and organic matter in the soil surface, were determined. Before and after grazing, images from the Sentinel-2A satellite were also obtained to observe the response pattern of pasture vegetation over time using the Normalized Difference Vegetation Index (NDVI) and Pasture Vegetation Coverage (PVC). The physical-hydric attributes of the soil were subjected to factor analysis. NDVI and PVC maps were evaluated for spatial variability. After the grazing period, there was a change in the attributes of the soil under study due to the animal trampling. Remote sensing (NDVI and PVC) highlighted patterns of variation, such as the reduction of pasture and possible areas of preference for the animals.

ABSTRACT Sugarcane has a great economic interest in Brazil, so it needs technologies to increase its yield strength, especially for seedling production. This study aimed to ascertain the influence of shading nets on early growth and development of pre-sprouted sugarcane seedlings. An experiment was conducted in a protected environment, in the Rural Federal University of Pernambuco (UFRPE), in Recife-PE, Brazil. The protected environments were covered with anti-UV low-density polyethylene plastic plus: Solpack® red ultranet net, Solpack® white net, Solpack® freshnet net, and without shade net, and five replications each. The experiment was carried out in a completely randomized design, and multivariate principal component analysis (PCA) was used to verify associations among cultivation modules, micrometeorological factors, and seedling growth parameters. Anti-UV low-density polyethylene + shade net improved seedling growth and development up to 27 days after planting. Higher substrate temperatures benefited early growth of seedlings. After 27 days of planting, sugarcane seedlings required higher air temperatures, as well as increased global and photosynthetically active solar radiation.

RESUMO Objetivou-se avaliar o efeito térmico na mudança comportamental e fisiológica de novilhas girolando, por meio da análise de componentes principais. A pesquisa foi conduzida na região Agreste do estado de Pernambuco, Brasil. Foram utilizadas três novilhas submetidas ao sistema de pastejo contínuo. Para determinação do efeito térmico sobre os animais, foram registradas as variáveis temperatura de bulbo seco e umidade relativa do ar, o que permitiu determinar o índice de temperatura e umidade e a entalpia específica. As variáveis fisiológicas monitoradas foram a frequência respiratória, temperatura retal e temperatura de pelame. Os indicadores comportamentais quantificados foram andando, bebendo, comendo, ruminando e ócio, para determinação da porcentagem de tempo despendido em cada comportamento. As variáveis do estudo foram submetidas a análise exploratória e descritiva, para inferência do grau de associação dos componentes principais. A análise multivariada permitiu estabelecer o grau de pertinência entre os sinais fisiológicos e padrões comportamentais associado ao ambiente térmico, que indicaram adaptação das novilhas ao pastejo contínuo, mesmo em condições meteorológicas críticas.

ABSTRACT The objective of this study was to evaluate the thermal effect on the behavioral and physiological changes of Girolando heifers by means of principal components analysis. The research was conducted in the Agreste region of the state of Pernambuco, Brazil. Three heifers submitted to the continuous grazing system were used. For the determination of the thermal effect on the animals, the variables dry bulb temperature and relative air humidity were recorded, which allowed to determine the temperature and humidity index and the specific enthalpy. The physiological variables monitored were the respiratory rate, rectal temperature and skin temperature. The quantified behavioral indicators were walking, drinking, eating, ruminating and leisure, to determine the percentage of time spent in each behavior. The variables of the study were submitted to exploratory and descriptive analysis, in order to infer the degree of association of the main components. The multivariate analysis allowed to establish the degree of pertinence between the physiological signs and behavioral patterns associated with the thermal environment, which indicated heifers adaptation to continuous grazing, even in critical meteorological conditions.